Sugar Acetylene for New Stereocontrolled Synthesis.
1994; Society of Synthetic Organic Chemistry, Japan; Volume: 52; Issue: 11 Linguagem: Inglês
10.5059/yukigoseikyokaishi.52.968
ISSN1883-6526
Autores Tópico(s)Catalysis for Biomass Conversion
ResumoC-Glycosidation is of great significance since it contains the introduction of carbon chains to sugar chirons or sugar nuclei as chiral pools. Silylacetylenes are sufficiently reactive to form sugar acetylenes for the selective introduction of acetylenic groups to sugar rings. Bis-C-glycosidation allows introduction of two sugars at both ends of a bis (trimethylsilyl) acetylene. A 2, 3-dideoxyglucose derivative provided the corresponding C-1 α acetylenic compounds, which would increase the scope of C-glycosidation with silylacetylenes. An alkynyl group attached to the anomeric position of a pyranose ring was epimerized through a dicobalthexacarbonyl complex by treatment with trifluoromethane sulfonic acid. Three steps involving cobalt complexation, acidic transformation and decomplexation afforded overall epimerization and thus prompted us to provide either the α or β alkynyl C-glycoside as desired. Ring opening of a dihydropyran derivative using Nicholas-type cation intermediates was also an accomplished part of this study.
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